Bottles for dripping fluid into a patient, and which are intended to be hung in an inverted position, are well known, and many devices have been proposed for hanging these bottles in an inverted position.
One such recently proposed hanging device is as shown in U.S. Pat. Nos. 3,635,367, and 3,744,658, and this type of bottle with such a hanging device is as shown in FIG. 8. The hanging device has a ring-shaped part 20 with an opening 21 in the center thereof through which the bottom of the bottle is exposed. A bail or hanger member 23 is, when the bottle is not in use, positioned within the aperture, lying in the plane of the ring shaped part 20, an integrally attached to the inner periphery 22 of the aperture 21 by hinge portions 24. The cap member and bail are molded from a flexible synthetic plastic material, such as polyethylene, so that the bail can be pivoted away from the bottom of the container into a position in which it projects generally away from the bottom of the container by twisting the hinge portions 24. The bail is then hooked over a horizontal hanger, hook, or the like for supporting the bottle in an inverted position.
However, depending upon the type of fluid which is contained in the bottle and which is being dripped into the patient, it may be necessary to keep a constant and accurate watch on the amount of fluid which is delivered from the bottle. For certain types of vascular contrast medium, for example angio- or arteriography contrast medium, the angiography or arteriography is performed after a certain amount of the contrast medium has been infused into the patient, and again after a certain additional amount of the medium has been infused. In such cases, it is necessary to read accurately the amount of fluid which has been infused by inspecting the graduations on the sidewall of the inverted bottle. If the bottle has not been hung in a perfectly vertical position, however, the level of the fluid in the bottle cannot be accurately determined.
When such a bottle is hung by a hanger as shown in FIG. 8, the bail 23 does not always extend perfectly perpendicularly away from the plane of the bottom of the container, due to the resiliency of the plastic material of which the hanger is molded, so that the bottle tends to hang in a slightly tilted position with respect to the vertical.